This device is a locking device to hold one or a plurality of control levers in a static position. A spring actuated over center hinged plate is provided with apertures that may constrain the movement of the control lever through interaction with a projecting rod mounted on the control lever.
The prior art includes devices that restrain the movement of control levers. The most obvious types of devices utilize spring loaded detents that may be overridden by an operator when the detented lever is displaced with a certain degree of force. Shift levers of automobiles often are guided by a shift gate that assists in proper gear selection. These gates have been designed in certain cases to positively lock out given gears that are not engaged during normal driving. Reverse gear would be an example.
Shift levers have also been designed where a latch mechanism has been incorporated into the lever that would be fingertip controlled to release the lever. This also prevented inadvertent gear shifts.
The closest prior art known by the Applicant involves a transmission lever lockout device where a spring biased plate having a slot formed in the active portion, so as to make a U-shaped plate, can be flipped over to engage the shift lever and prevent relative fore and aft displacement.
The device does not positively prevent the movement of the lever as the lever would still be free to move horizontally through the slot in the plate.
In off-highway construction equipment such as an articulated four wheel drive loader having a boom mounted hydraulically operated scoop at the front end thereof it is occasionally necessary to maintain the levers controlling the scoop hydraulics in a neutral position. This is oftentimes necessary when the vehicle is being serviced and the sccop would be at rest on the ground. With the levers restrained in neutral an accidental jostling of them such that the scoop is moved may be prevented. This invention is directed at providing a positive lever location maintenance trap that serves this purpose.
It is also occasionally desirable to maintain the hydraulic scoop control in neutral when the vehicle is being driven, towed on the road or towed on a trailer. Thus a device, such as this invention, that would not be disengageable by vibration is desirable. The spring of this apparatus will tend to keep the device engaged in situations where normal vibrations may rattle a lever without the device out of a neutral position.
The instant invention includes a plurality of advantages that make it more desirable than the prior art known to the Applicant. Among these advantages is that the device will positively lock the control lever in a neutral position relative to the lever's path of normal travel assuming the path is parallel to the horizontal rod.
Another advantage is that the horizontal rod portion is removable from the control lever. This allows the control lever dust boot to be taken off and replaced over the handle of the control lever rather than necessitating the complete removal of the lever to replace the boot or gain access to the lever fulcrum cover box.
Another advantae of this device is that the spring tension will be predictable in both the engaged and disengaged positions. When engaged the hinged portion is prevented from going beyond a horizontal deployment. Also, when disengaged the hinged portion is prevented from going beyond a predetermined point. As both these engaged and disengaged positions are predeterminable then only a spring with appropriate characteristics, primarily length and tension can be selected. Spring selection would yield a spring that would always be under some tension thus preventing it from needing a positive attachment device to ensure it stays engageable.
Another advantage is that the structure of the horizontal rod includes an arcuate rod stop that functions to locate the horizontal rod and also to provide increased strength in the control lever in the area where the control lever has been drilled through to except the horizontal rod.
Another advantage is that this invention can be retrofitted to unequipped machines with only minimal modifications of the machine.
The device is inexpensive to manufacture yet capable of being sturdily constructed to provide a control lever location maintenance trap that will maintain the lever in a predetermined location.